Event for when JDA encounters an exception

Take errors such as below and turn it into an event so we can deal with it as we’d like instead of it forcibly being pushed to the console as stack traces tend to scare people who don’t know what they are/shouldn’t need to be concerned with them.

[Mon, 3. Apr 2017 19:47:32 ERROR] [JDA] Encountered an exception:
[Mon, 3. Apr 2017 19:47:32 ERROR] [JDA] com.mashape.unirest.http.exceptions.UnirestException: java.net.SocketException: Connection reset
    at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:143)
    at com.mashape.unirest.request.BaseRequest.asString(BaseRequest.java:56)
    at github.scarsz.discordsrv.dependancies.jda.core.requests.Requester.execute(Requester.java:122)
    at github.scarsz.discordsrv.dependancies.jda.core.requests.ratelimit.BotRateLimiter$Bucket.run(BotRateLimiter.java:301)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at sun.security.ssl.InputRecord.readFully(Unknown Source)
    at sun.security.ssl.InputRecord.read(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readDataRecord(Unknown Source)
    at sun.security.ssl.AppInputStream.read(Unknown Source)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:139)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:155)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:284)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:140)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:167)
    at github.scarsz.discordsrv.dependancies.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
    at github.scarsz.discordsrv.dependancies.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
    at github.scarsz.discordsrv.dependancies.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
    at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:138)
    ... 10 more
[Mon, 3. Apr 2017 19:47:32 ERROR] [JDA] RestAction queue returned failure: [ErrorResponseException] Discord returned an error with no defined error-code : null

[MinnDevelopment]

Exceptions and errors that are caught by JDA internals are passed into respective sections of the API. This means you can handle them through the ExceptionEvent or for RestAction with the failure callbacks. The logging of timeouts and requester errors is intentional behavior and I don’t want to change it since it seems unnecessary and misleading. Timeouts and HTTP issues should be at a minimum for proper functioning communication anyway, if an issue rises it should most certainly be logged including the stacktrace for better issue prevention. JDA attempts to retry on an HTTP timeout once if it occurs, if that retry fails as well we will print the timeout exception to alert the end user of the faulty connection. Since JDA makes use of the SLF4J api it is possible to configure the logger to ignore or filter out any exception, although I highly discourage from ignoring them.

My mentioned concerns and the fact this issue has been stale for such a long time are reason enough to close the thread.

[Scarsz]

Having an ErrorHandler interface might be an effective implementation for this. JDABuilder::setErrorHandler, have the default/unspecified behavior be to an implementation that reflects JDA’s current behavior.